Compass follow-up



April 20, 1937. w. MOLLER ET AL l COMPASS FoLLo'w-u P Filed May 4, 19 54 2 I i 8 l I W 1 6 2% w m Q? m 3 11o 108 A 52 49 g N 44 Q 210 5 0 Inventor:

Patented Apr. 20, 1937 UNITED STATES PATENT OFFICE COMPASS Waldemar Miiller and Gerhard Zoege von Manteuflel, Berlin-Zehlendorf, Germany I Application May 4, 1934, Serial No. 723,854 In Germany May 8, 1933 11 Claims." (01. 33-204) This invention relates to compasses, more particularly for aircraft,.and one of the objects of the'inventi'on is to provide acompass that is supportedor steadied by suitable means as for ex-' ample by a gyroscope'and which shall meet all.

demandaand in all positions and under all con-- ditions shall give a correct and perfectly undisturbed indication of the magnetic north direction and shall furnish a perfectly reliable read- Broadly the invention also contemplates the provision in a conveyance, in aircraft for example, of apparatus to fix the'direction of a first dynamic field (the north-south direction for 1.3 example) with relation to the undisturbed surface level of a second dynamic field subjected to strong disturbances (for example with relation to the horizontal plane), using for this purpose supporting or steadying means (a gyroscope rotatable about a vertical axis for example), in re-' spect to said second dynamic field, and a direction indicator (a magnet system rotatable about a vertical axis for example) for said first dynamic field, supported by said supporting means, and

characterized by the fact that a body member rotatable about an axis has said axis confined or held by said supporting means to the direction of said second dynamic field (the true vertical for example) and is sumultaneously adjusted by said direction indicator about saidconfined axis in the direction of said first dynamic field, said supporting means being preferably provided with means responsive to said second dynamic field to release or initiate or disturb the i equilibrium of pairs of forces which tend to re-,

turn the axis of rotation of said supporting means to the direction of said second dynamic field.

These and such other aims and objects of the invention as may hereinafter appear will be readily understood from the following description taken in connection with the accompanying drawing of one embodiment of the invention tion.

conveyance in which the apparatus is to be used. The upper and lower plates of said casingv are shown in section at 2 and [in Fig. 1. In the illustrative embodiment of the invention shown in Fig. 1, a frame or ring 6 is journaled at 88 in said plates 2 and l for rotation about a vertical axis. A Cardan or gimbal frame or ring [0 isjournaled at l2l2 in said frame or ring 6 and 'in turn has'.journaled therein for rocking movement upon ahorizontal axis (not shown) perpendicular to the axis of said: journal II, a

I magnet system supporting-means, including the magnet system housing l4. Said housing 14 comprises two parts It and I8. The spindle 20 carrying the magnet system 22 is journaled in the part IS. The spindle 24 of a'gyroscope rotor 26'is journaled for rotary movement at 28 in said housing part l8, the axis of rotation of said rotor being in parallelism with theaxis of the spindle 20 aboutwhich said magnet system 22 is adapted to rotate, It will be apparent'that rapid rotation of said rotor- 26 will tend to maintain its axis of rotation in its normalor correct position in space, thereby to maintain the compass spindle in the truly vertical direction, so that said compassbeing uninfluenced by lateral accelerations will indicate the true magnetic north direction.

It is well known that a free gyroscope gradually undergoes deviations from its initial position or direction, by reason of the unavoidable friction in the journals and thepresent invention therefore contemplates the provision of suitable means to overcome or correct this defect. In the illustrative embodiment of the invention said means conveniently comprises devices responsive to theaction of gravity which upon any tendency of the magnet system to deviate from the true vertical,

release or render operative a force or system of' forces which immediately acts to restore said magnet system spindle to its true vertical posi- In the illustrative embodiment of the invention said devices conveniently comprise two pairs of pendulating members which control outlets for compressed air. While any suitable means may be used to drive the gyroscope rotor 26, it has therefore been found convenient to drive the same with compressed air which may be supplied from any suitable, source not shown through a. pipe 30 to the journal bearing 32 from which it passes-through openings 3| into a passage 36 provided in the frame 6 and thence through ports 38-38 into a chamber 40 provided in the secondary Cardan suspension frame I 0. From said chamber the compressed air passes ports 4849 to drive the rotor 26.

terior of the housing part l8 the compressed air passes through pipes 5650 into the lower part of the other housing part l6 whence the compressed air will issue through two pairs of ports 52-52 and 5454. Only one of the latter is visible in Fig. 1. The two ports 52 are in a plane at right angles to that containing the ports 54. A pair of members 56.-56 are pivoted at 56 to opposite sides of said housing part l6 and are thus adapted to pendulate in front of said ports 52, 52 responsive to the action of gravity. A

similar pair of pendulating members, operating in the same manner, are adapted to cooperate similarly with the two ports -54. They are not shown in the drawing.

When the axes of the magnet system and of the rotor 26 are exactly perpendicular, the pendulating members 56, 56 will be so positioned relatively to the two ports 52, 52 that an equal amount of compressed air will escape from each of said ports. If, however, thespindle 20 of the magnet system deviates from the perpendicular, the arrangement is such that one of the outlet ports 52 will be more covered by its cooperating pendulating member and the other port 52 will be more uncovered by its pendulating member. The strength of the current of air issuing from one of said ports 52 will differ from the strength of the air current issuing from the opposed port 52, so that by the action of said air currents upon the ambient air the housing l4 will be swung toward the side from which issues the weaker current about an axis perpendicular to the axis about which said pendulating members 56, 56 swing.

bient air and tend to return the spindle 20 to its original normal position or direction. The gyroscope 26 suffices to keep the magnet spindle 20 sufficiently near the true vertical direction in the case of disturbances of relatively short duration due to theforces-of acceleration; the compressed air streams issuing from the outlet ports 52, 52 and 54, 54 prevent slow deviations of the axes of said gyroscope and magnet system from a vertical position due to precessional.movements of the gyroscope.

Preferably the magnet system itself will not be used to indicate the direction but the Cardan system frame or ring 6 will be used for this purpose, and in accordance with the invention, suitable means are therefore provided to cause said frame to take part in or move with said magnet system in the latters movement about the axis of its spindle 20 said ring 6 thus conveniently conthe invention compressed air will preferably be used to move said frame 6 with said magnet system. To this end the interior of the compass housing l8 communicates with the chamber 60 in the housing part l6. A partition 62 forms a second chamber 64 in said part l6, said partition being provided with two ports 66, 66. The chamber 66 is separated from the lower chamber having the ports 52 by means of a wall 68 provided with three bores or passages l0, 12, 14. The passage opens into the atmosphere and communicates with the chamber 64. Passages l2 and 14 communicate with said chamber 64 through ports l6, 18 respectively. Compressed air projected from the chamber 66 through said ports 66, 66 will thus enter said ports 16, I8 and passages l2, l4, respectively,.said ports 66, 66 being in substantial alignmentwith said ports l6, '18 respectively.

Means are herein provided for varying the effects of the fluid pressure by controlling the passage of the fluid pressure from said ports 66, 66 to said ports l6, 18, so as to vary, relative to each other, the degree of fluid pressure delivered by said ports 66, 66 to said ports 76, 18 respectively. Said controlling means may be of any suitable construction without departing from the scope of the invention and herein conveniently comprises a disk 80 secured eccentrically to the magnet system spindle in a plane between said ports 66, 66 on the one hand and said ports 16, 18 on the other, the arrangement being such that the ports l6, 18 will be more or less covered by said disk according to its angular position. The relation between the degree of fluid pressure delivered to said ports 76, I8 respectively will thus vary ac- .cording to the angular position of said disk, and

correspondingly the fluid pressure in said passages l2 and 14 respectively.

A chamber 82 is provided upon one side of the housing part I8, said chamber containing ,fluid pressure responsive means, herein comprising conveniently a plurality of diaphragm chambers, herein two such diaphragm chambers 64, 84 being provided. The chamber 82 is connected by a passage 86 with the passage '52 and the interior of said diaphragm chambers is connected by a passage 88 with the said passage 14, so that said differential pressure diaphragm chambers are adjusted in correspondence to the position of the magnet system 22 relative to the housing l8. Movements imparted to said differential pressure diaphragms are transmitted through a lever and link system to a slide valve 92 working in said previously mentioned slide valve chamber 42, said valve 92 controlling two sets of nozzles 94 and 96 respectively (Fig. 2). For this purpose the compressed air chamber 46, which communicates by pipe ,44 with said slide valve casing 42, is, by mo ement of said slide valve 92, caused to communicate with either an opening 98 leading to the jet nozzle pair 94 or with an opening I00 leading a to the jet nozzle pair 96. In the one case compressed air will be projected from the jet nozzle pair 94 and in the other case from the jet nozzle pair 96. As said pairs of jet nozzles are located perpendicularly to the plane of the Cardan system frame 6, and are directed in opposite directions the movement, communicated to said frame 6 will be either clockwise or contraclockwise about its axis 8-8 according to which one of said jet nozzle pairs is operated. Said frame 6 will 'thus take part in or follow the movement of said magnet system 22 aboutthe axis of. its spindle.

The above referred to linkage system is dia-.

grammatically shown in Fig. 3, wherein the diaphragm'of the diaphra'gmchamber 8 is connected by link I 2 If to-T'a: shaft- I- 23"journalled in fixed bearings I 25, I26. 'Saidshaft will thus be rotated correspondingly to the movements of 5 said diaphragm,'that is to say, tothe movements of the magnet-system and these movements will be communicated to'th 1 e29 throughlever I30, rod I32, lever'i'Ifl sha I v fixed'bearings 136}. I 38- rid lever-j 2.2:

duration of the magnet system suitable means may be provided for. thispurpose'within;

the scope of the invention, but inthe illustrative embodiment of the invention a secondgyroscope I02 is conveniently provided for this purpose, Said gyroscope I02 rotates about'a horizontal axis I04 mounted in a frame I06 which is rotatable about a horizontal axisv extendingth'rough journals I08 in a frame or brackets IIIl carried by the housing I8. Said gyroscope I02 operates asa turn indicator gyroscope and produces precessional movements of the gyroscope frame I06 about the journalslll8 correspondingly to the speed of rotation of the frame 6' about the axis. passing through the journals 8-.v

Said gyroscope I02, may driven by any suitable ineans, compressed air-being herein-conveniently used for that purpose which issup'plied to the periphery of the gyroscope rotor through a pipe I-I2 which communicates with the interior of the housing part I8. The damping action of said gyroscope I02 is increasedby connecting itsframe I06 in the manner,oi airestoring-means or device with the slide valve 7 I of a suitable lever andlink. 'connection diagrammatically represented .irr Fsigy 3; said lever" and link connection herein comprises a link [I4 con- 40 necting the gyroscope frameiIIlG to. a lever I46 which isin turn connected to shaft- I40, the latter being connected by; level- I42 ,tosaidyalve 92. The angular speed impartedztothe frame 8 by the compressed air jets issuing from the pairs of j'et nozzles 94 or 95' causes the gyroscope frame I06. to precess andthese precessional movements return the slide valvemember 92 to its median position by means diTsaid lever and link system I I4, thus gradually the: jets of compressed air issuing from-said ijetnozzle pairs 94' or 96, so that said-dram ,ijsbrbught'to rest aperiodically. i" I The magnet system andsaid gyr0s0ope-there-.

fore act upon said vertical} frame in a manner; analogous to the action'ofa direction indicator on the automatic and ofameas-v uring means acting responsiveto the turning speed, in some cases. in combination or cooperation with restoring Itwill be seen that the stability-is increased,- in the-"case of automatielcontrols, by causing other forces or infiuences'toact upon the control, andwhich are derived from the speed of rotation or turning speed and in cases also and also restoring devices.

We are aware that ourpresentinvention may be embodied in. other, specific, forms from that herein described without departing from the spirit tion to be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

' I40 dournalle d" in- Means will preferably. be {provided 5m; accord ance with the invention to render "saidfram'e 't uninfluenced or unaflected by oscillations of short mber gl' by means from the acceleration of. the turning movement,

or essential attributes thereof, and we therefore desire the present embodiment of said inven-.

steering Indicator, an automatic steering apparatus or one or more supplementary or additional compass cards, as willbe readily understood by those skilled in the art.

We claim:

1. A compass follow-up comprising, in corn- Said frame 6 could be used for actuating a v bination, a magnet system rotatable about a ver- I tical axis; a stabilizing gyroscope with a vertical spinning axis; a turn-responsivegyroscope-ineluding a rotor having a horizontal spinning axis and a rotor bearing frame mounted for oscillation in horizontal bearings at right angles to said spin axis; a follow-up ring rotatable about a fixed substantially vertical axis; a common supporting member for said magnet system and said gyroscopes,,means journalling said supporting mem- 2.A-compass follow-up comprising, in combination, a magnet system rotatable about a'vertical axis; a gimbal ring; a supporting member for said magnet system, journaled for horizontal oscillation in said gimbal ring; a follow-up ring pivotally supporting said gimbal ring, about a horizontal axis at right angles to said first-named horizontal oscillation axis, said follow-up ring I being rotatable about a fixed substantially vertical axis; differential air flow means controlled by the relative angular displacementof said supporting member and said magnet system, including a pair of nozzles; means for conducting air under pressureto said nozzles; a second, pair of nozzles positioned opposite to and adapted to reeeive at least a part 'of the air flow from the nozzles of said first pairrespectively; means adapted to intercept said air flow and controlled by said magnet system; means adapted to exert a torque about the vertical axis of said followup ring, including nozzles emitting jets of air under pressure directed against the ambient air; means .f orconducting air to said nozzles; and means responsive to differential pressure created "by said magnet system controlled air flow means to control the admission of air to said-nozzles, a

' -3, For use in a'conveyance, the combination of a gyroscope spinning about a vertical axis; a

magnet systemv rotatable about a vertical axis; a common housing supporting said gyroscope and magnet system;- a universal suspension for said hous ing including a Garden frameand a ring carrying the journal about which said flame is rotatable, said ring being rotatable about a fixed vertical axis in said conveyance; a sec-' ond gyroscope carried by said housing for spinningabout a substantially horizontal axis and for precession about a second horizontal axis at right angles to said first axis; v into action by relative rota on of-said ring and magnetsystem from a normal relation, tending to apply a force to move said support to restore said relation,- and means oper-.-

wer means. brought ated by precession of said second gyroscope, as a resultof said restoring means, tending to diminish the power applied by said power means,

4. A compass follow-up comprising, in combinatlon, a magnet system; supporting means in and relatively to which said magnet system is rotatable about a vertical axis; a stabilizing gyroscope having a vertical spinning axis and a second turn-responsive gyroscope having a horizontal spinning axis and including a rotor bearing member rotatable about a horizontal axis at right angles to the spin axis, both of said gyroscopes carried by said supporting means; a universal mounting, including follow-up means, in which said supporting means is mounted for unl versal movement, said follow-up means being rotatable about a fixed substantially vertical axis; talk applying means adapted to iotate said follow-up means about said vertical axis, said talk applying means being partially controlled by said second gyroscope and rendered operative by relative rotary movement of said magnet system and said supporting means, thereby restoring the normal relation between said magnet system and said supporting means.

5. A compass follow-up comprising, in combination, a magnet system rotatable about a vertical axis; a stabilizing gyroscope with a vertical spinning axis; a common supporting member for said magnet system and said gyroscope; airring, said follow-up ring being rotatable upon a fixed substantially vertical axis; difierential airfiow means controlled by relative angular devia- ,tion of said magnet system and supporting member and including a pair of nozzles; means for conducting air under pressure to said nozzles; a second pair of nozzles positioned opposite to and adapted to receive at least a part of the air flow from the nozzle of said first pair respectively; means adapted to intercept the air flow between the respective pairs of nozzles and controlled by said magnet system; means adapted to exert a torque about the vertical axis of the follow-up ring, including third nozzles emitting jets of air under pressure against the ambient air; means for conducting air to' said third nozzles; and means responsive to difierential pressures between said first andsecond pair of nozzles adapted to control the admission of air to said third nozzles.

6. A compass follow-up comprising, in combination, a magnet systemrotatable about a vertical axis; a turn-responsive gyroscope, including a rotor having a horizontal spinning axis carried by a rotor bearing frame; a Cardan ring; a common supporting member for said magnet system and said gyroscope mounted for horizontal oscillation in said Cardan ring,'said rotor bearing frame being mounted for oscillation about horizontal pivots in said supporting member; a follow-up ring supporting said Cardan ring, said follow-up ring being rotatable about a fixed sub.- stantially vertical axis; differential air flow means partly controlled by tipping movement of said rotor bearing frame of said turn-responsive gyroscope and rendered operative upon relative azimuthal deviation of said magnet system and said supporting member, said air fiow means including a pair of nozzles; means for conducting air under pressure to said. nozzles; a second pair of nozzles positioned opposite to and adapted to reand said ceive at least a part of the air flow from the nozzles of said first pair respectively; means adapted to intercept the air flow between the respective pairs of nozzles and controlled by said magnet system; means adapted to exert a torque about the vertical axis of the follow-up ring, including third nozzles emitting jets of air under pressure against the ambient air; means for conducting air to said third nozzles; and means responsive to differential pressures between said first and second pair of nozzles adapted to control the admission of air to said third nozzles.

. ing a rotor having a horizontal spinning axis carried by a rotor bearing frame mounted for oscillation about horizontal pivots at right angles to said spin axis; a stabilizing gyroscope having a vertical spinning axis; a common supporting member for said magnet system and said gyroscopes; a universal mounting about horizontal axes for said supporting member, including a Cardan ring and a follow-up ring pivotally supporting said Cardan ring, said follow-up ring being rotatable about a fixed substantially vertical axis; airports in said supporting member;

' means for conducting air under pressure thereto; pendulous shutters cooperating with said airports to control air jets emitted from the latter to apply a righting torque to said supporting member upon tilting movement of the same; differential air ficw means controlled by relative azimuthal deviation of said magnet system and supporting member and including a pair of nozzles; means for conducting air under? pressure to said nozzles; asecond pair of nozzles positioned opposite to and adapted to receive at least a part of the 'air flow from the nozzles of said. first pair respectively; means adapted to intercept said air fiow between the respective pairs of nozzles and controlled by said magnet system; means adapted to exert a torque about the vertical axis of said follow-up ring, including third nozzles emitting jets of air under pressure against the ambient air; means for conducting air to said nozzles; means responsive to diflerential pressures between said first and second pair of nozzles adapted to control the admission of air to said nozzles; and an operative connection between said rotor bearing frame of said turn-responsive gyroscope last-named air-controlled means, whereby said turn-responsive gyroscope tends to diminish the action of saiddifierential pressure responsive means.

8. A compass follow-up comprising, in combination, a magnetsystem rotatable about a vertical axis; a turn-responsive gyroscope, including a rotor having a horizontal spinning axis and a rotor bearing frame mounted for oscillaair under pressure to said nozzles; a second pair of nozzles positioned opposite to and adapted to receive at least a part of the air flow from the nozzle of said first pair respectively; means adapted to intercept said air flow between the respective pairs of nozzles and controlled by said magnet system; means adapted to exert a torque about the vertical axis of said follow-up ring, including third nozzles emitting jets of .air under pressure against the ambient air; means for conducting air to said third nozzles; a slide valve controlling the supply of air to said third nozzles; means responsive to difierential pressure between said first and second pair of nozzles to actuate said slide valve; and a link system connecting the piston of said slide valve to the rotor bearingframe of said turn-responsive gyroscope.

9.A compass follow-up comprising, in combination, a magnet system rotatable about a vertical axis; a turn responsive gyroscope including a rotor having a horizontal spinning axis and a rotor bearing frame mounted for oscillation about horizontal pivots at right angles to said spin axis; a stabilizing gyroscope having a vertical spinning axis; a common supporting member for said magnet system and said gyroscopes; a universal mounting on horizontal axes for said supporting member, including a gimbal ring and a follow-up ring pivotally supporting the latter,

said follow-up ring being rotatable about a fixed substantially vertical axis; airports in said 'supporting member; means for conducting air under pressure to said airports; pendulous shutters cooperating with said airportsto control air jets emitted from said airports, to apply a righting torque to said supporting member upon tilting movement of the same; differential air flow means controlled by relative azimuthal deviation of said magnet system and said supporting member and including a pair of nozzles; means for conducting air under pressure to said nozzles; a

second pair of nozzles positioned opposite to and under pressure against the ambient air; means for conducting air to said third'nozzles; a slide valve controlling the supply of air to said third nozzles; means responsive to differential pressures between said first and second pairs of nozzles to actuate said slide valve; and a link system connecting'the piston of said slide valve to the rotor bearing frame of said turn-responsive gyroscope. i

10. A compass follow-up comprising, in combination, an element responsive to the earths magnetic field; follow-up means rotatable in azimuth; power means to rotate said follow-up means in azimuth; control means responsive to 'relative azimuthal deviation of saidfollow-up means and said element and adapted to control said power means; a gyroscope including a rotor and-a rotor, bearing member carried by .said follow-up means, said gyroscope being rotatable in precession about an axis'at right angles to the spin axis of said rotor responsive to rotary. movement of said follow-up means; and an operative connection between said control means and said rotor bearing. member of said gyroscope, whereby the power applied by said power means is diminished upon rotation of said follow-up means in azimuth.

' 11. A compass follow-up comprising, in combination, a magnetic system rotatable in azimuth; follow-up means rotatable in azimuth; power means to rotate said follow-up means in azimuth; control means responsive to relative azimuthal deviation of said follow-up means and said magrotation of said follow-up means in azimuth.

WALDEMAR MiiLLER. GERH. ZOEGE voN MANTEUFFEL. 

